While the present mandrel invention can be used in any suitable coated belt production system, it will be described herein for clarity as used in the production of belts useful in electrostatic marking systems.
By way of background, generally, in a commercial electrostatographic reproduction apparatus (such as copiers/duplicators, printers or the like), a latent image charge pattern is formed on a uniformly charged photoconductive or dielectric member. Pigmented marking particles (toner) are attracted to the latent image charge pattern to develop such image on the dielectric member. A receiver member, such as paper, is then brought into contact with the dielectric member and an electric field applied to transfer the marking particle developed image to the receiver member from the dielectric member. After transfer, the receiver member bearing the transferred image is transported away from the dielectric member and the image is fixed or fused to the receiver member by heat and/or pressure to form a permanent reproduction thereon. In a typical fusing process where the toner is fused to the paper or receiving media, two rolls or belts are used through which the paper travels during the toner fusing. One roll or belt, usually the harder roll or belt, is a fuser member, the second is the pressure member or the softer roll or belt. “Fuser or pressure member as used throughout this disclosure includes both rolls and belts.
Typical pressure rolls or belts (“Softer Member”) that are used in a fusing system have an elastomeric coating like silicone rubber which may or may not have a thin layer of another material over the surface of the member. A functional nip is formed when the softer member is pressed into the fuser member (“Harder Member”). The fuser member generally comprises a metal core with a hard Teflon (™ of DuPont) coating or thin elastomer.
The pressure or softer members are typically constructed of a cylindrical steel core or rod having positioned over it an elastomer or rubber material cylindrical coating. In any system when a hard (fuser member) is pressed against and contacts a softer member, nips are formed throughout the length of the pressure member in contact with the fuser member. These pressure zones ultimately cause the softer material to contact the support plates and create wear, shortening roll life and causing debris in the system. Also, once excessive wear takes place and an uneven nip is formed because of uneven coating, improper fusing of the toner can result causing imperfect copies on the paper or receiving member. In addition, because of this wear problem caused by non-precise surface coating, frequent changes requiring new softer members are required. Generally, the elastomeric members have typically been manufactured from a single elastomeric material, such as silicon rubber, of a uniform hardness as determined by a durometer. From both a cost standpoint and performance standpoint, any improvement in the softer and harder member, construction that would extend roll life and improve performance at the fuser station would be very desirable. Also, eliminating an uneven nip and material deterioration of the pressure member would extend pressure and fuser member life and substantially improve fusing performance. An improved method for precisely coating fusing members will substantially eliminate or lessen deterioration of these fusing members.
Prior to the present invention, this was no efficient and inexpensive method to securely hold onto a large (such as a) 300 mm diameter belt during the surface coating steps. An efficient system is needed to allow a user to apply precision coatings and execute precise process steps in making fusing members or other coated belts.